1. Field of the Invention
The present invention relates to a parallel link robot, a parallel link robot system, and a method of controlling a parallel link robot.
2. Description of the Related Art
There are existing parallel link robots having a plurality of parallelly disposed arms that cooperatively move an end effector. There are also existing parallel link robots that can detect dislocation of a joint of an arm (see, for example, Japanese Unexamined Patent Application Publication No. 2009-248289).
Japanese Unexamined Patent Application Publication No. 2009-248289 discloses a parallel mechanism (parallel link robot) that includes a plurality of electric motors (drive sources) and a plurality of arms respectively driven by the plurality of electric motors. Each arm of the parallel mechanism includes first and second links that are connected to each other through a ball joint (joint portion). The ball joint includes a spherical head, a socket that holds the spherical head, and a conductor that electrically connects the spherical head and the socket to each other. The parallel mechanism disclosed in Japanese Unexamined Patent Application Publication No. 2009-248289 determines whether or not the ball joint (joint portion) is dislocated on the basis of the continuity of the conductor disposed between the spherical head and the socket.
However, the parallel mechanism (parallel link robot) disclosed in the Japanese Unexamined Patent Application Publication No. 2009-248289, with which dislocation of the ball joint (joint portion) can be detected on the basis of the continuity of the conductor of the ball joint (joint portion), has a problem in that the structure of the ball joint (joint portion) becomes complex because the conductor, which electrically connects the spherical head and the socket to each other, is disposed between the spherical head and the socket.